On evil

"On Evil" ("De Malo") represents some of Aquinas's most mature thinking on goodness, badness and human agency.

Together with the second part of the Summa theologiae, it is one of his most sustained contributions to moral philosophy and theology and ranks among his major writings.

In it, Aquinas examines the full range of questions associated with evil: its origin, its nature, its variety, its relation to the good and its compatibility with the existence of an omnipotent, benevolent God.

This edition offers Richard Regan's translation, based on the Leonine Commission's authoritative edition of the Latin text.

Brian Davies has supplied an exhaustive introduction and notes.